"I've tried the war office," Robert paced the small library, two pairs of eyes, Mary and Isobel's following his every step. "There is something going on. All they'll say is that there are heavy casualties again among those involved in the battle at Lys. There has been trouble at Messines. And they did confirm that Matthew's regiment was involved.

"I'm very sorry we can't get anything more from them. We're just going to have to wait. They did agree to call me as soon as they hear news – one small perk from having connections," his voice tailed off.

He turned towards them, unable to quell the anguish in his eyes and went on. "I don't like this. That you both could feel… and Daisy too. Carson tells me she had a turn and she's beside herself. She's telling them over and over that William has been hurt. He shook his head. "I don't like this. I don't like this at all."

There was nothing for it. They would have to wait.

Robert returned, worried, to his luncheon guests. Mary and Isobel returned to the hospital in silence, their shared sense of foreboding heightened by Robert's news.

Mary attempted to re-start her budget task. When it proved impossible to concentrate she settled instead for sorting her office desk and drawers. The papers needed a tidy anyway, and at least that was a job she could focus on.

Isobel returned to the ward. "Any news?" Sister Thomsen inquired in a low voice. Isobel shook her head. "Very little. But his regiment is involved in the battle at Lys," she said tightly, her mouth a thin line. "… and Daisy is beside herself about William.." She shut her eyes momentarily and put her hand to her lips. "Distract me, for god's sake!"

"Of course my dear. Help me with Lieutenant Jones. I'm not sure how we best clean the wound where he has developed that secondary skin infection," Sister Thomsen said immediately, and she led her gently across the room to where the young man lay groaning on his bed.

Arriving home at the end of her shift, Molesley greeted her with a cheery smile. "Ah, Mrs Crawley," he beamed. "Good evening. We've had some mail today, and you'll be pleased to hear there is a letter from Matthew."

His smile faded as he saw Isobel's face drain of colour at his words, and he caught her arm as she swayed.

"Mrs Crawley, you're awfully pale. Is something wrong? Here, sit down a moment," and he helped her to the seat by the telephone in the hall.

"Molesley," Isobel began, vaguely thinking she should tell him what Robert had said... what she, Daisy, and Mary had worried. But she just couldn't. Instead, she said "The letter, could you..."

"Of course," Molesley replied, worried by his employer's countenance. "Do you wish to read it here? Or could I assist you to the sitting room? You don't look at all well!"

At Isobel's gesture, he took her arm and soon had her in the sitting room seated in the comfortable armchair by the fireplace.

He fetched the letter from the mail tray and handed it to her. "I'll organise you some tea. A long day was it?" He frowned at her, trying to fathom what could be the matter. She nodded distractedly, her hands already ripping at the envelope. Molesley hadn't moved, the slight frown still on his face. He clearly expected more of an answer. Suppressing her irritation, Isobel put her hand to her forehead and said, "A headache I'm afraid. A draught would be helpful."

Satisfied, Molesley turned on his heel and left the room. Isobel unfolded the letter, smoothed out the cream coloured paper and began to read.

April 3 1918

Dear Mother,

We are due shortly to go over the top. I can't say when, of course. And this time I can't shake my unease. Everything around me feels sharpened. The air feels like it has a weight to it. The light is brighter. People's voices are louder. The extremes of colour we get here, even they seem deeper somehow. The mud is blacker, and yet the sky holds such drama and depth with the scudding clouds and changing light it is like a Turner painting. It is so beautiful I just want to lie back and watch it all day.

And whilst I brood, William remains positive and unflappable. He is a great comfort. I find I rely on him more and more for courage of late. Strange. To rely on a younger man for such a thing. The war has made me feel old. I can't believe it's been going more than three years now. When we started out we were all convinced it would be 'over by winter' and now it's the fourth winter.

Mother, what are we doing? In these moments when I see everything with such clarity, I see these young men we shoot. They look like us. They have mothers, sisters, wives, brothers and fathers like us. No doubt they had both ordinary and extraordinary lives before this, just like us. I've lost count of how many men I've killed. And how many countless others I have instructed my platoons to kill. I can't reconcile it in my mind. It haunts me, Mother.

What would Father have made of this madness? He was a healer. I often wonder what he would say if he were here and able to offer his good counsel to our Government. Surely there is another way to make things right, and what better than a man focused on healing to chart the path? I miss him so much, Mother. And I wish I knew what would he advise me, his son, in charge of a company of 200 men, on the cusp of yet another battle.

Mother, I will be all right. You know how my mind works. And how I need to write like this because it helps. 'A burden shared is a burden halved' as you have counselled me since I was a small boy.

I am with good men over here, and they keep me cheered. We are battle hardened and we know what to do. And I do know how to lead.

Whatever happens, please know that I love you so very, very much, and I am enormously proud to be your son.

With all my love,

Matthew

The call from the war office came at 3:30 am. Carson roused Lord Grantham first. He and Cora hurried to the telephone in the hall. As Robert listened, Cora asked Carson in a low tone, to raise Daisy, Mrs Patmore and her daughters.

A few minutes later, summoned from their beds by Carson and Mrs Hughes, the family, along with Daisy and Mrs Patmore assembled to hear Robert's news.

By God, he thought. This is when you don't want to be the head of a household. He took a breath and steeled himself to share the news.

"They are both alive," he said to a collective gasp of relief, "but," and he held up his hand for silence, "both of them are wounded…" he paused, breathing hard, and then as he looked at their stricken faces, he made a snap decision not to share in full the rest of the message. He just couldn't. Perhaps the war office had it wrong: maybe when they were here there might be some hope.

"And that's it?" whispered Edith. "Seriously wounded," he finished. Mary's face went white. Daisy let out an anguished sob.

Robert looked around at his family and the assembled servants and saw the fear for cousin Matthew, and William the popular footman in their solemn faces. They had been so lucky until now, the immediate household mostly unscathed, unlike both neighbouring estates, one of which had lost four out of five sons. But now the war really had come to Downton.

"What happens next Papa?" Edith spoke her bottom lip quivering.

"They are working to get them home. The expectation is late tomorrow."

"I need to call Isobel," Mary said, almost to herself. "And we need to get hold of Lavinia." She turned and walked quickly across to the telephone.

Cora took a deep breath. "Mrs Patmore," she said. "Would you mind making tea and bringing it to the small library for us all. And perhaps Daisy needs something too," she said looking sadly at the crying girl. Mrs Patmore bustled off, and Mrs Hughes followed her back to the stairs, her arm around Daisy's shoulder.

It was the hardest telephone call Mary had ever had to make. In the interminable silence after she told Isobel, she had a sudden urge to howl like a child, acutely aware of what the news must sound like to Matthew's mother. She hung up the receiver and stood silent for some minutes. Finally, she took a deep breath, steeled herself, and called Lavinia.

Lavinia's tearful words on the end of the telephone were a lot easier to deal with. After she bade Lavinia good night, thinking vaguely that she really should have said good morning despite the inky blackness outside, she walked unseeingly to the small library to join her family and lowered herself slowly into a chair.

She still loves him, Robert saw with startling clarity as he watched her come in. He'd suspected as much. And for the life of him, he still couldn't understand how their relationship had got so messed up. He shook his head. And now it might be too late.

They were a silent knot of worried people, unsure just what to do next.

Sipping his tea, Robert looked around at his daughters. The true graveness of the situation that he had not fully revealed caused him to reflect for a moment on what the war had already meant for them.

Youth cut short. News, all too frequent, of yet another childhood friend dying in a foreign field. The carefree days of social calls, dress fittings and elegant soirees a distant memory. Not what he or Cora had envisaged for the well-bred young women they had raised.

He had not expected to have daughters that worked. And yet here they all were, doing just that. And in a most diligent and dedicated fashion. What was it he felt? No, it wasn't outrage. Nor a sense of 'this shouldn't be.' It was pride. Today, in the midst of a long-running and brutal war, he was proud of them. Intensely proud.

Mary, his eldest, was showing a real flair for management with her administration of the now significantly expanded Downton hospital. And she'd surprised him and Cora when she'd added to her work by becoming a volunteer nurse. And what's more, she seemed to be genuinely enjoying it. She's always been so unreadable. Yet in her nursing she shows a real empathy and gentleness with the patients, he mused.

Sybil. Looking at his youngest daughter he couldn't help but smile. His sweet spirited and opinionated child had blossomed into a forthright, dedicated young woman, and she was now a fully qualified nurse, and being paid! Hmm. He still wasn't sure what he thought about that. Her sense of humour and fun, if anything, seemed even more pronounced, and she was very popular with her patients, and particularly those at the convalescent home where she was involved in the provision of the physical therapy.

Edith was perhaps the most different. The daughter he'd struggled to relate to was quite transformed. From the early days after the convalescent home had opened she had taken it upon herself to see to the patient welfare at Downton Abbey, gradually building her expertise and role, and with it, her reputation among the patients and medical staff alike. Her care and helpfulness towards the men had even earned her a special mention from General Sir Herbert Strutt, for god's sake, when he had visited the convalescent home during his troop recruitment drive in the previous year.

Robert took a deep breath and swallowed. "My dearest daughters," he said finally. "I don't think we can achieve much more just waiting. How about you try and get a little more sleep." He paused and then said grimly, "We're going to need our wits about us in the coming days. It will not just be our people who will need us. The casualties from these last few days have been very high."

Edith and Sybil left first. Mary lingered. Robert could see she wanted to say something, but the words weren't coming. He went across to her and took her hand. "Mary…" He gave her a searching look, but he couldn't find the words to say anything either. Finally, he said, "You need your sleep." She nodded and slowly stood up, and he hugged her briefly before she silently left the room.

Cora and Robert followed her upstairs. When they got to their room, Robert gave a shuddering sigh, and sat heavily on the edge of his bed, staring unseeingly.

"Robert, what is it?" he felt Cora's hand on his shoulder. "They told you something else didn't they?" she said gently.

"Cora, it was a very strange call. I couldn't bring myself to say it to you all, but the phrase they used was 'critically injured.' And it was more what they didn't say which had me worried. If… if there was hope they would have been sent to one of the major field hospitals. But what they said was they were on their way here directly, here to an auxiliary hospital that is only set up to deal with moderately injured men… Cora, I, I think they have been sent home to die!"